I just updated both my desktop and my laptop versions of P3D with the latest version 3.4.22.19868. Both updates reported to be successful. My desktop is a Windows 7 machine and is loaded with third party addons. The laptop is a Windows 8.2 machine and has a "plain jane" install with no third party addons whatsoever. After the updates, my desktop is still showing version 3.4.18.19475 (which was what was showing before the update) and my laptop is showing 3.4.14.18870 (don't know what it was showing before). I'm checking the version numbers via the Help-->About Lockheed Martin menu item.

I am pursuing an error message on the Majestic Q400 forum and was told I must be certain I have the latest version of P3D. When I load the Majestic Q400 aircraft I get an error message indicating the "gauge version must be used under Prepar3d V3.2". The Majestic Q400 is the latest version.

I used the "Setup_Prepar3D.exe" to install it. But I went back and used your instructions and using the Install_Client.msi and it corrected the problem. Do I need to do the same thing with the Content and Scenery msi or did the initial "Setup_Prepar3D.exe" that I used properly install them?

The update didn't fix the problem with the Majestic Q400...still getting the error message but the aircraft seems to be working fine. That's a matter for the Majestic forum.